Polarity reverser



E. 1. BALLUFF. Poumnv' nEvERsER.

APPLICATION FILED APR. H. |920.

Patented Oct. 10, 1922.

nde

Patented oct. 13o, 1922.

UNITED sTAiLEs,

PATENT OFFICE.

EDWARD J. BALLUFF, or CHICAGO, ILLINOIS, AssIGNoRoF ONE-HALF 'ro ELMEII.srA'rz, or CHICAGO, ILLINOIS.

POLARITY. nEVERsnIt.

Application filed April 14,`

To all whom t may concern:

Be it known that I, llilnwannfl. BALLUFF,` a citizen of the UnitedStates, residing at Chicago, in the county of Cook and Sta-te ofIllinois, haveinvented certain new` and` useful Improvements in aPolarityReverser, i A of Which the following is a specification.

The general object of the invention is to reverse the direction ofcurrent through the pointat which the circuit is interrupted at frequentintervals to prevent corrosion and deterioration of the mechanicalelements making contact atthis point.

@ne important application of my invention is `to timers for the ignitionsystem of internal combustion engines andthe object thereof is morespecifically to kprovide current reversing means built into the timermechanism as a unitary device.

Another yobject is to provide means for changing the direction ofcurrent every time the circuit is interrupted. l v A, Another object isto provide a reversing arrangement ink which no lead Wires need `carrycurrent to movingparts.

Another object is to arrange the parts and the electrical circuitssothat current is never interrupted except by. separation of the timercontacts so that the mechanical elements used to reverse the connectionsare not subject .to destructive arcing.

Further objects and advantages of my in-,

Vention Will become apparent as the descrip-v tion proceeds.

Iii the accoiiipai'iying drawings, Figure 1 is a plan view of a timer.With the cover removed. F ig. 2 is a section onthe line 2-2 of Fig. l.Fig. 3 is a section on line 3-3 o`f\Fig. 2, and Fig. 4 is adiagrai'ninatic view .of the circuits l prefer to employ.

ln the embodiment of my invention selected for illustration, the timershaft 10 extends upwardly through a sleeve 12 shown as formed integralwith the lovver Wall 14 of a cylindrical casing 16 having a suitablecover 18.

With a roller 22 to actuate a lever'24 pivoted at 26 and carrying. atits outere'nd a contact point 28 adapted to rest againstan adjustablecontact screw 30. The support for the lever 24 is a removable partition32 resting on At its yupper yend 'the :shaft 10 carries the usualcameleinent 20.contacting y 1920. l Serial No. 373,723.

spacedlugs 34 carried byy the casing 16 and preferably attached theretoby set screws 34a. Aicoil spring 36 engaging a stationary pin 38 on thepartition 32 operates to hold the'lever 24 against the cam 20.

`The reversing `mechanism I have illus- `trated comprises a rocker' 40housed in the casing 16 below the partition 32 and driven by aneccentric'yf42 carried by the timer shaft 10. The rocker `has anelongated slot to accommodate they eccentric 42 and is pivoted at oneend at 44 to the partition 32 which is preferably of metal. The free endof the rocker carries a pair of brushes 46 and 48 which slide back andforth in contact With .segments mounted on the under side of aninsulating cleat 50 suitably fastened over cut-away portion of thepartition 32.

The eccentric 42 has a projecting lip 52 adapted to support the Weightof the rocker 40 and may if desired, be attached to the timer shaft 10by a set screw (not shown) and operate to support the Weight of thetimer shaft itself.

y Referring to Figs. 3 and 4, the contact elements I prefer to employcomprise a` pair of continuous segments 54 and 56 and outer segmentsseparated into three sections. The brushes carried by the rocker makecontact at all` times With the continuous segments and each brushconnects its continuous segment With thesection of theadjacentdiscontinuous segment over which it happens to lie. i

With the brushes in the position indicated in dotted lines on Fig. 4,current will flovv as follows-from the battery 57 through seg-Vcircuitthrough which current can flow, and therefore if the timercontacts open, the current will be interrupted and an electrical impulseWill be generated in the secondary Windin of the induction coil.

Similgarly, When the brushes have moved to the upper end of theirstroke` as shown in Fig. 4, current will flow as yfollovvs-from` thebattery 57 through segment 56, brush 48, section 63, Wire 74, `section61,- Wire 76,

central section 72, and Wire 66,1@0 thetimer llo.

Contact 28, and from the other timer con tact 30 through wire 64,central section 62, Wire 78, section T1, Wire 80, section 76, brush 46,segment 54 and thence as before through the induction coil. It will beseen that when the brushes are in this position, the direction ofvcurrent through the timer contact points is reversed. The end contacts68 and 73 be ing directly connected by Wires '74 andV 8O to the oppositeend contacts 6l and 7l the circuit through them will be identical withthat last traced except for the omission of end contacts 63 and 73 andthe `wires 74 and 80. p

For a four cylinder car, the parts should be arranged as illustrated',the cam 2O opening the timer contacts to deliver an impulse when therocker 40 is in the middle of its stroke. Another impulse will bedelivered When the rocker is at one endv of its stroke, a third as itreturns to the vmiddle position, and a fourth at the other end of thestroke. Each of these impulses will be delivered with the currentpassing through the timer contacts in the opposite direction from t-hatwhen the previous impulse was obtained. The sparking. action between thecontact points Will therefore not tend to form a crater in one contactand a tit on the other and the contact points Will remain smooth andclean for a much longer period of time on this account.

The brushes 46 and48 are preferably long enough to bridge the gaps inthe discontinuous segments as they pass from one section to the next ofsaid segments. This will cut the timer contacts out ofthe circuit, thecurrent flowing as followsMwhen the brushes are bridging the upper gapshown in Fig. 4. From the battery through segment 56, brush 48, section62, Wire 78, section 7l, wire 80, section 73, brush 46, segment 54 andthence through the induction coil. It would therefore be impossible toproduce an impulse by separating the timer contacts wvliile thebrushes'were in. a position to bridge either of the gaps in the outersegments. This however, does not interfere With the operation of thedevice as the times for opening the timer contactsl may be readily soplaced that the impulse comes when the brushes are entirely over one setof contact elements. It Will be seen thatthe flow of current is neverinterrupted so. as to cause a spark between the brushes 46 and 48 andthesections With Which they make contact. These parts therefore may be madeof material best adapted to withstand the mechanical Wear of slidingContact as they will be not ysubjected'to arcing andthe resultantcorrosion.

Vilhile I have illustratedand described in ldetail; the preferredembodiment of my invention, it should be clearly understood that thedisclosure is merely for purposes of illustration and that man ymodifica tions and variations will naturally occur t-o those skilled inthe art. I aim in the subjoined -claims to cover all such legitimatevariations and modifications.

l claim as my invention l. .In a device of the character described, acasing, a partition therein, a timer shaft, timer contacts operativelyassociated with the shaft, a rocker pivoted to the partition, aneccentric adapted to actuate the rocker, and an insulating support, saidrocker and support having cooperating contacts adapted to periodicallyreverse the direction of current through the timer contacts.

2. In a device of the character described, a centrally located timershaft, a pivoted rocker, an insulating support, cooperating contacts onthe rockerand the support, timer contacts associated With the shaft, andan eccentric on the shaft adapted to actuate the rocker.

3. In a device of the class described, a casing, an apertured partitionin said casing, a centrally located timer shaft, timer contactssupported my said partition and operatively associated with said shaft,a rocker below said partition and pivoted thereto, an eccentric on saidtimer shaft adapted to act-nate said rocker, andan insulating supportcovering the aperture in said partition, said support and rocker havingcooperating contacts adapted periodically reverse the direction ofcurrent through said timer contacts. v

4. In a device of the class described, a easing, an apertured artitionin saidcasing, a centrally located timer shaft, timer contacts supportedby said partition and operatively associated With said shaft, a rockerbelow said partition and pivoted thereto, an eccentric on said timershaft adapted to actuate said rocker, and an insuh'tting supportcovering the aperture in said partition, said support and rocker havingcooperating contacts adapted to periodically reverse the direction ofcurrent through said timer contacts, said reversal being timed to occ-urwhen said'timer contacts are closed.

5. In a device of the class described, a pair of continuous segments anda pair oi adjacent discontinuous segments each divided into threesections, brushes, and means for moving said brushes back and forth oversaid segments, timer eoiitacts, and `Wiring connections between saidtimer contacts and said segments and between cert ain of said segments,adapted to reverse the current"- through said timercontacts each timesaid brushes move from one section of said discontinuous segments toanother section.

6. In a device of the class described, a pair of continuous segments anda pair of adjacent discontinuous segments each dividedinto threesections, brushes, and means l. il

iso

ybrushes move from one section of said dis-y continuous segments ltoanother section, said ybrushes being adapted to move from one sectionto` another during each closed interval of said timer contacts, wherebyalternate openings of ysaid contacts are subjected to arcing in.opposite directions.

7. In a device of thek class described, a pair ofcontinuous segments anda pair oft adjacent discontinuous segments each di- `vided into threesections, brushes, and means for moving said brushes back and forth oversaid segments, timer contacts, and wiring connectionsbetweensaid timercontacts and said segments and between certain of said segments, adaptedto reverse the current through said timer contacts each time saidbrushes move from one section of said discontinuous segments to anothersection, said wiring being so arranged that the circuit is never brokenexcept at said timer contacts.

8. In a device of the class described, a pair of continuous segments anda pair of adja cent discontinuous segments each divided into threesections, brushes, and means for moving said brushes back and forth oversaid segments, timer contacts and wiring connectionsfbetween said timercontacts and said segments and between certain of said segments, adaptedto `vreverse the current through said timer contacts each time saidybrushes move fromone section of said dis-y continuous segments toanother section, said brushes being long enough to bridge the gapsbetween adjacent sections, said bridging action operating to cut thetimer contacts out of the circuit but making no other change in thecurrent.

9. In an electrical system, mechanical means forv periodicallyinterrupting a current, and means for automatically changing thedirection in which the current fiows through said interrupting means,said direction-changinq means comprising an eccentric, an insulatingsupport and a rocker, said support and rocker having cooperatingcontacts, said means operating without interrupting the flow of current.i

In testimony whereof, I have `hereunto set my hand.

, ,y EDWARD J, BALLUFF.

